Paperboard container lids having circular geometries which include spirally wound side walls or skirts are well known, as evidenced, for example, by U.S. Pat. No. 1,760,029 to Wright et al. Such circular paperboard lids are well suited to being produced using conventional paperboard tube winding machines. Specifically, in order to produce circular lids having spiral-wound side walls, conventional paperboard tube winding machines may be used to produce a cylinder comprised of spirally wound paperboard sheets. The cylinder is thereafter cross-sectioned to form a plurality of individual circular rings which are mated with respective circular closure disks by crimping the edges of the rings and disks together in a known manner.
Recently, foodstuff containers having non-circular geometries have been provided and have achieved widespread appeal in the marketplace. These containers have been provided with conformably shaped non-circular lids which are formed of a single ply skirt whose ends are adhered to one another in overlapping relationship thereby forming a generally vertical seam. The thus formed non-circular skirt may then be mechanically joined to a conformably shaped non-round closure disk in accordance with conventional paperboard forming techniques.
According to the present invention, conventional spirally-wound circular side walls may be re-formed into non-circular geometries so as to then be mechanically joined to conformably shaped non-circular closure disks. Therefore, conventional paperboard tube winding machines may be employed as in the past to provide individual ring sections that may be re-formed into non-circular geometries and thereafter mated with conformably shaped planar closure disks. In such a manner, conventional paperboard tube winding machines may now be employed in processes to form both non-circular and circular container lids, thereby increasing the efficiencies of such conventional machines.
Further aspects and advantages of the present invention will become more clear after careful consideration is given to the following detailed description of the preferred exemplary embodiments which follow.